TUE HUMAN SPECIES. 151 



since the Pachyderms of the United States, as well as those 

 of the Pampas of Brazil, are much more perfect, and, in many 

 cases, possess characters ascribed to bones in a recent state. 

 Alligators and crocodiles, moreover, continue to exist in lati- 

 tudes where they endure a winter state of torpidity beneath ice, 

 as an evidence that the great Saurians in that region have not 

 yet entirely worked out their mission ; whereas, on the old 

 continent, they had ceased to exist in high latitudes, long before 

 the extinction of the great Ungulate. The vast extent of sandy 

 alluvial territory, from the Gulf of Mexico to the summit of 

 Long Island, appears as if it were a late deposit, in part debris 

 of the Mexican and Caribbean portions of the continent, car- 

 ried north, and thrown off when the Gulf Stream was formed. 

 At the mouth of the Mississippi, the sea, of small depth along 

 the whole coast, continues to recede before the delta of the 

 river ; and the Florida and Carolina shores northward form a 

 series of lagoons on the ocean side. The stream rushes 

 onwards in a north-cast direction, and with a gradually de- 

 creasing velocity and temperature (though both are still very 

 perceptible off New York), until it is finally neutralized at 

 Nantucket, and the last particles of deposit suspended in it are 

 precipitated to form the banks of Newfoundland. A continent 

 torn asunder and washed away alone could furnish the immense 

 alluvial surface and submarine banks here noticed. The rivers 

 of the United States and Canada are not of a nature to have 

 added more than feeble deltas, such as that of the Hudson at 

 Sandy Hook. Great changes are commemorated by the Indians 

 in their mythological and legendary tales, both in the direction 

 of th< tides and in ancient accumulations of ice.* 



THE PACIFIC. 



The Pacific and South Seas are likewise replete with evi- 

 dence of great geographical mutations ; some have already 



*See Appendix. 



